A vehicle including a stepped transmission possibly generates a deviation between an operating position of a manual valve coupled to a shift lever and an operating position of a pressure regulating valve based on an instruction signal with an inhibitor switch to detect a position of the shift lever (hereinafter, such deviation is referred to as “discrepancy”). This is because that a sensing range (a conductive area) by the inhibitor switch is configured slightly wider than a switching range of the manual valve. The discrepancy occurs, for example, when the shift lever is held at an intermediate position between an N range and a D range to move the shift lever from the N range to the D range. In this case, the instruction signal by the inhibitor switch becomes a signal corresponding to the D range. On the basis of the instruction signal by the inhibitor switch, instructed pressure to a clutch heightens. However, the manual valve remains at a position corresponding to the N range; therefore, hydraulic pressure is not supplied to the clutch. Afterwards, the movement of the shift lever up to the D range sets the manual valve at a position corresponding to the D range, thereby starting supplying the hydraulic pressure to the clutch. At this time, the instructed pressure to the clutch with the pressure regulating valve has already heightened. Accordingly, the start of supply of the hydraulic pressure to the clutch possibly causes a rapid increase in hydraulic pressure in the clutch. This suddenly engages the clutch, possibly causing a large engaging shock.
In contrast to this, Japanese Patent Application No. 2007-052398 discloses a reduction in an instructed pressure to a clutch in case of discrepancy.